He’d been below par for much of the race but Nairo Quintana proved best on stage 17 on Wednesday, racing to the second Tour de France stage win of his career. The Colombian attacked on the last of three climbs on what was a unique 65 kilometre stage to Saint Lary-Soulan/Col du Portet, caught those ahead of him and soloed in first.

Dan Martin (UAE Team Emirates) initially went with Quintana but was dropped; he chased the Movistar rider all the way to the summit but finished 28 seconds back.

However the biggest story of the day was the all-guns-blazing general classification battle. Third place went to race leader Geraint Thomas (Team Sky), who tightened his grip on the yellow jersey by finishing at 47 seconds, five ahead of Primoz Roglic (LottoNL-Jumbo) and Tom Dumoulin (Team Sunweb).

Steven Kruijswijk (LottoNL-Jumbo) was sixth, one minute and five seconds back, while four-time Tour winner Chris Froome cracked when Dumoulin surged with two kilometres to go. He rolled in one minute and 35 seconds behind Quintana, showing the strain of riding four consecutive Grand Tours.

In dropping 48 seconds to Thomas, Froome likely lost his chance to win the Tour. Dumoulin jumps up to second overall, one minute 59 seconds back, while Froome is now at two minutes 31.

“The truth is this is a well-deserved victory. Not only for me but also for my team who worked really hard and aggressively for that,” said Quintana. “We’ve demonstrated to being a great team. I knew the course. I reconned the final climb but what made me win is above all the support of the squad, and especially Alejandro Valverde who waited for me and put me in a fantastic position.

“The overall classification has become a bit hard but we keep our intention to make the race difficult till the end and this victory gives us the serenity for what comes next.”

The day’s other big victor was Geraint Thomas, who reinforced his place atop the general classification.

“It was a tough day. I was feeling all right,” he said, with characteristic understatement. “It was a hard start to that last climb. Obviously Quintana went, Roglic chased, Froomey was with him. We forced Dumoulin to ride for a bit. And that was really on. Then it settled down a bit.

“I was feeling pretty good so I would just react as soon as Roglic or Dumoulin moved. That is what I had to do. It was a good day.”

Thomas was asked about teammate Froome’s ride on the climb. “He wanted to try to do something so he went early with Roglic,” he said. “I just assumed he was going to be good. He wasn’t feeling too great towards the top. I think he is still third, still up there.”

Dumoulin improves that place in the general classification but drifts from one minute 50 seconds back to one minute 59 adrift. There is still a mountain stage to go as well as a time trial stage – Dumoulin’s speciality – but he realises he is running out of time if he is to win the race overall.

“I always keep a little bit of faith, a little bit of hope,” he said, speaking of his chances. “But so far in the last two and half weeks, Thomas has proven to be the strongest. That is the situation now. For me, so far it is not possible to get time on him. That is it.”

Roglic remains fourth overall but drifts a little further back from yellow. He is now at two minutes 47 seconds, while Quintana jumps three places to fifth. He is now three and a half minutes back but with just one mountain stage ahead and a time trial still to dispute, a podium finish remains unlikely. Kruijswijk overtakes Mikel Landa (Movistar) to move into sixth overall.

Also advancing was Martin, who wanted the win but was relatively satisfied with his second place. “I knew I had good legs,” he said. “I knew I felt good. I knew the tempo was good. But it was just a case of riding my own rhythm. It was literally a time trial. If somebody caught me, I wasn’t even going to try to hold their wheel. I was just going to hold my tempo to the top, and obviously try to keep Nairo within sprinting distance. But I had a bad kilometre between four and three to go. He just pulled a bit more of a gap out and I couldn’t close it then.”

How it played out:

Stage 17 of the Tour de France was the most unusual of this year’s race; an extremely short, hard climbing leg designed to produce aggressive racing from the GC riders and stage hunters. The leg from Bagnères-de-Luchon to Saint Lary-Soulan/Col du Portet was the shortest road stage of this year’s event, being just 65 kilometres.

In fact, it was the briefest of the current century. In terms of Tour history, the shortest ever was in 1971, when José Manuel Fuentes won stage 15 between Luchon and Superbagnères. This was just 19.6 kilometres in length.

Wednesday’s difficulty was ramped up by the fact that the climbing began right from the drop of the flag. There were three climbs, with the first two being category one and the final ascent being hors categorie. These were the Montée de Peyragudes (km 15), 14.9 kilometres in length at an average gradient of 6.7%, the Col de Val Louron-Azet (km 37), 7.4 kilometres at 8.3% and the last climb, the 16 kilometre Col du Portet. This averaged 8.7%, but had much steeper sections.

The stage began with a much-hyped grid layout, mimicking Formula One. The riders were arranged in order of general classification, but suggestions of flat out racing from the GC riders proved unfounded. Once the flag dropped they stayed together, while the peloton’s opportunists scampered clear on the early slopes.

Those first attackers were Tanel Kangert (Astana), Thomas De Gendt (Lotto-Soudal) and Pierre Rolland (EF Education First-Drapac). Kangert pushed on ahead, while those two chasers were joined by 18 others.

Nicolas Edet (Cofidis) was chasing hard and got up to Kangert, but was dropped soon afterwards. He was then caught and passed by Tuesday’s stage winner Julian Alaphilippe (QuickStep Floors), who was hunting more points for his King of the Mountains jersey. Also there were Jesus Herrada (Cofidis) and Christian Durasek (UAE Team Emirates).

They in turn were chased by Marc Soler and Alejandro Valverde (both Movistar Team), Rafal Majka (Bora – hansgrohe), Omar Fraile (Astana Pro Team) and Dani Navarro (Cofidis). Kangert went over the top of the climb first, with Alaphilippe, Durasek and Herada 15 seconds back.

Alaphilippe and Durasek bridged to Kangert after 25 kilometres of racing. Kangert took the intermediate sprint at Loudenvielle (km 27.5) ahead of Durasek and Alaphilippe. Then, on the start of the day’s second climb, the Ag2r La Mondiale team ramped up the pace, with Pierre Latour pushing at the front in his white jersey of best young rider and Romain Bardet sitting behind him. At this point they were two minutes and 40 seconds behind the leading trio.

Latour cracked after his effort and slipped to the back of the yellow jersey group, with Marc Soler (Movistar) taking over at the front of that bunch.

Up ahead, Alaphilippe led Kangert over the top of the Val Louron climb, further strengthening his grip on the polka-dot jersey. Durasec was at five seconds, while Valverde, Martinez and Majka completed the top six, 35 seconds behind.

Green jersey wearer Peter Sagan (Bora-hansgrohe) crashed on the downhill but was able to get back on his bike. His points total will see him win a record-equalling sixth green jersey, but only if he reaches Paris. Pressing on after his fall was essential.

The fireworks start

Heading onto the final climb, Kangert pushed ahead of Alaphilippe, leading the stage with 15 kilometres left. Behind, Dan Martin (UAE Team Emirates) and Nairo Quintana (Movistar) attacked. The latter has had a quieter Tour than anticipated, starting the day eighth overall, four minutes 23 seconds back, and was keen to make amends. As for Martin, he took has had bad luck in the race and was two places further back, at six minutes 54 seconds.

Soon afterwards, Primoz Roglic (LottoNL-Jumbo) darted clear, seeking to improve on his fourth place overall. He was marked by Chris Froome (Team Sky). Tom Dumoulin had started the day just 48 seconds ahead of the Slovenian and was forced to chase. The Team Sunweb rider was going well and soon dragged Roglic and Froome back.

Out front, Quintana caught teammate Valverde and Majka. They were one minute and five seconds back with 11 kilometres left. However any thoughts of Valverde helping Quintana were dashed when he cracked and slipped backwards.

Team Sky led the GC group under the ten kilometre to go banner. That group included Thomas, Froome, Egan Bernal and Wout Poels, as well as Roglic and Steven Kruijswijk (LottoNL-Jumbo), Dumoulin, Romain Bardet (Ag2r-La Mondiale) and Mikel Landa (Movistar).

Quintana was riding strongly and caught Tangert with 8.5 kilometres left, Majka in tow. The Astana rider tried to stay with them but cracked. Martin was just 18 seconds back with eight kilometres remaining and was trying to close, while the yellow jersey group was at one minute and two seconds.

Poels led the yellow jersey group, followed by Bernal. The GC rivals of Thomas and Froome were biding their time and yet to launch their bids for yellow. Meanwhile Quintana cracked Majka with 6.5 kilometres left, pushing on alone towards what he hoped would be a stage win and GC improvement.

Battle for yellow

The summit was drawing closer and closer, and the action was heating up. Romain Bardet was dropped by the yellow jersey group and quickly lost ground while, with about 5.8 kilometres left for him, Martin caught Majka. Behind, Kruijswijk jumped clear of the latter bunch, only to be dragged back by Bernal.

With four kilometres left, Quintana was 29 seconds ahead of Martin and one minute nine ahead of the Thomas group. He was looking good for the stage win, but hard roads lay ahead and the GC riders had yet to really launch their attacks.

Roglic then moved, jumping away from the group. Thomas marked him, while Dumoulin jumped up to them. Froome was distanced and appeared to shout on the radio at Bernal to wait.

He rejoined but Dumoulin seemed to know he was not going well. The Dutchman launched a move with two kilometres to go and while he was marked by Thomas, Roglic and Kruijswick, Bernal, Froome and Landa were immediately dropped. Dumoulin continued to drive to open the gap, with Thomas staying glued to his wheel.

Dumoulin flicked his elbow at Roglic, who came through and started riding. Meanwhile, a minute and two seconds ahead, Quintana went under the kilometre to go banner and into a mountain tunnel, impassively climbing towards the stage win.

Roglic then played his hand, surging clear. Thomas went with him, while Dumoulin was distanced but inched his way back up to them with a kilometre to go. Roglic continued to drive hard, mindful that they were gaining time on Froome. Behind, his teammate Kruijswijk was chasing hard, trying to get back to that group.

Quintana raced through to take the win, 28 seconds ahead of Martin. Thomas jumped clear for third, 47 seconds back, while Roglic and Dumoulin finished at 52 seconds. Kruijswijk conceded a further 13 seconds, but the big story of the day was Froome only finishing eighth, losing 48 seconds to Thomas and sliding to third overall.

That marks Thomas out as the clear leader for Team Sky. That plus his increased margin over Dumoulin puts him in a very good position to win the Tour on Sunday, but he said he isn’t looking that far ahead.

“I don’t want to let myself think about it. Honestly, it is just day by day,” he said. “A sprint day tomorrow; I will rest up now and get ready for that.”

Thomas added that he sees Dumoulin and Roglic as his big challengers, categorising Froome as a teammate rather than a rival, saying that he believes Froome will try to bounce back from his tough day.

“He is a fighter,” Thomas said. “I am sure he will keep fighting all the way. It is a good to keep that advantage for myself, and the team are in a great position now.”